The 'dogs' would not be all on one side as shown in your sketch. If there are 4, I would expect to see one central on each side. For a full height door, it's more likely to be one at top and bottom and two at each side. The hinges are likely to be similar to a rudder's pintle and gudgeon with the gudgeon on the door. The doors are prevented from riding up by washers and split pins on the pintles.